Purpose <p>The effect of AMP deamination (AD) on the skeletal muscle bioenergetic system in constant-power exercise to exhaustion of different durations/intensities is studied.</p> Methods <p>A computer model of the skeletal muscle bioenergetic system, involving the each-step-activation mechanism of system activation during work transitions and P_i double-threshold mechanism of muscle fatigue, is used.</p> Results <p>The effect of AD on the system is stronger and more beneficial in extremely intense exercise (EIE) than in very intense exercise (VIE) and intense exercise (IE). Namely, in IE, AD accelerates P_i increase, shortens very significantly the time to exhaustion, slightly enhances the ATP/ADP decrease (harmful effects), does not affect significantly AMP and pH, and attenuates ADP increase (beneficial effect). In VIE and EIE, AD accelerates P_i increase and moderately shortens the duration of exercise (harmful effects), significantly attenuates the ATP/ADP and pH decrease (beneficial effects), and very significantly lowers the ADP and AMP increase (strong beneficial effects). Generally, the more intense the exercise, the greater are the beneficial effects and the smaller are the harmful effects. AD prevents significant cytosol acidification during muscle recovery after exercise. The slow AMP and total adenine nucleotide pool (especially ATP) resynthesis during recovery accelerates ADP and pH, and delays P_i return to the resting value.</p> Conclusion <p>The main advantageous physiological role of AMP deamination is attenuation of the harmful effects of the AMP, ADP, and H⁺ increase during and after very intense exercises.</p>